We read with interest the article by Goldschlager et al1 entitled
"Etiologic Considerations in the Patient With Syncope and an Apparently Normal Heart." This topic has recently become relevant to addiction medicine, in particular the field of opioid agonist therapy for heroin abuse. Despite the fact that persons addicted to opioids are relatively young and generally lack structural heart disease, they may be susceptible to arrhythmic syncope.